Thread guide for sewing machines



Fig. 2

' F. w. MAUQUOI THREAD GUIDE FOR SEWING MACHINES Filed Sept. 15, 1966 INVENTOR. Fred W. Muuquoi ATTORY United States Patent 01 Thee 3,407,761 Patented Oct. 29, 1968 3,407,761 THREAD GUIDE FOR SEWING MACHINES Fred W. Mauquoi, Roselle Park, N.J., assignor to The Singer Company, New York, N.Y., a corporation of New Jersey Filed Sept. 15, 1966, Ser. No. 579,548 4 Claims. (Cl. 112-218) ABSTRACT OF THE DISCLOSURE A thread guide for a sewing machine comprising an elongated plastic member having thread receiving grooves disposed longitudinally thereof. The grooves are constructed and arranged so that the thread is resiliently retained within its corresponding groove.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to sewing machines and in particular to a novel and improved thread guiding means for handling the passage of thread therethrough and which combines light weight, simplicity of design, relatively low manufacturing costs, minimum resistance thread guiding surfaces, among other distinct advantages, and especially being composed of a material, such as plastic, for resiliently retaining the thread in the grooves of the thread guide member.

Description of the prior art It is known in the art to provide a sewing machine with a thread guide in order to prevent entanglement of the threads among themselves or with any other external object. However, the prior art devices are commonly designed such that a relatively high resistance to the passage of thread is present resulting in a possibility of uneven thread delivery. Additionally, the cost of manufacturing the prior art devices has been high when compared with the cost for manufacturing the device of the present invention. This is due to the fact that the thread guide of the present invention contains a minimum number of components and may be manufactured in a simple manner. Typical of the prior art thread guides are those shown and disclosed in the United States Patents to Osterhout, No. 1,253,518, Jan. 15, 1918, Becker, No. 1,728,158, Sept. 10, 1929 and Clayton, No. 1,996,040, Mar. 26, 1935.

SUMMARY OF THE INVENTION The present invention overcomes the prior art deficiencies by providing a thread guide composed of a plastic type material having the characteristic of being resilient. The use of this kind of material allows the thread guide to be made by an extrusion process and thus results in a significant reduction in manufacturing costs. This type of material presents a relatively low resistance to the passage of thread and therefore substantially eliminates the problem of an uneven flow of thread. The design of the present thread guide member makes threading relatively easy in view of the readily accessible longitudinal slots located therein and also substantially decreases the possibility of the thread becoming disengaged from the guide grooves or slots while still allowing the thread to flow freely when the machine is in operation. Because the thread guide disclosed herein is composed of a plastic material it can be manufactured relatively easily and cheaply as an integral unit requiring no additional components to provide the desired function of guiding the thread therethrough. Thus by using an extrusion process to manufacture the subject thread guide a minimum of manufacturing steps are required to produce the resultant product.

Accordingly, it is an object of this invention to provide for a sewing machine a novel and improved thread guide member that is simple, economical, durable, efficient and dependable, and that will provide for proper thread flow during operation of the machine.

Another object is to provide an improved thread guide member particularly adapted for use on a feed-ofi-thearm type sewing machine.

It is a further object of this invention to provide a novel and improved thread guide member which is of l ght weight and easily threaded.

It is also an object of this invention to provide a thread guiding means having a low resistance to thread flow, thus allowing the thread to flow freely, but yet resiliently retaining the said thread so as to substantially preclude any inadvertent unthreading thereof.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a feed-olf-the-arm type sewing machine embodying the invention.

FIG. 2 is an enlarged sectional view of the thread guide member and associated parts, taken substantially on the line 2-2 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to the drawings, the present invention is illustrated in FIG. 1 as embodied in a feed-oif-the-arm type sewing machine substantially as illustrated in the aforementioned United States patent of Clayton, No. 1,996,040.

The illustrated machine comprises a frame including a bracket arm 1 which terminates at its free end in a head 2 in which is mounted a reciproc'atory needle-carrying bar 12 and presser bar 15. A needle clamp 14 is connected to the lower end of needle bar 12 and holds the needles 13 in position. The presser foot 16 is secured to the lower end of the presser bar 15.

The bracket arm 1 is carried at the upper end of a standard 4 which is integral therewith and mounted on a bed 5. The bed 5 is substantially U-shaped and comprises an arm 6 upon the rear portion of which the standard 4 is mounted, and which extends horizontally forwasdly therefrom, a horizontal arm 7 extending laterally from the forward portion of arm 6, and a horizontal work arm 8 extending forwardly from arm 7 and terminating in a free end directly beneath the head 2. A plurality of fins 11 are located on the underside of horizontal arm 7 for the dissipation of heat.

Actuation is imparted to the needle bar 12 by a main shaft (not shown) journaled longitudinally of the bracket arm 1 and extending through the end wall thereof at the end opposite from the head 2. Upon the free end of the main shaft is mounted a hand wheel 3 adapted to be belt driven from a source of power. A casing or cover 9 encloses a standard type drive mechanism which synchronizes the feeding mechanism and the lower stitchforming mechanism of the machine arranged within the work arm 8 with the actuation imparted to the needle bar by the aforementioned main shaft (not shown) so as to produce the desired stitching.

The cover plate encloses the mechanism located within work arm 8. A conventional throat-plate 17 is located at the free end of work arm 8 substantially below the head 2.

A plurality of threads 18 are led from a thread supply (not shown) to a fan-shaped guide plate 19 which has a plurality of apertures or threaded eyelets located therein and is mounted on the casing 9. The threads 18 are then led from the guide plate 19 to an elongated thread guide member 20 which is mounted on the casing 9 and has a plurality of longitudinally thread grooves 22 (see FIG. 2) located on the upper surface thereof. The grooves are formed on a raised portion of a base member 21. The member 20 is preferably an integral unit composed of a vinyl plastic material in order to impart to the member, in particular the thread grooves, the characteristics of resilience and low resistance to the thread flow. The member 20 is mounted on the casing 9 in a conventional manner by the use of a plurality of screws indicated by the reference numeral 27.

It is seen in FIG. 2 that each of the longitudinal thread guide slots 22, through which the thread actually flows, is respectively formed by a pair of groove lip members 2344. These lip members define the side walls of their respective groove and together with the base member 21 form an integral thread guide member. Preferably, each of the paired lip members respectively define equal but opposite angles with the base member 21 such that the resultant groove has a narrow opening at the top, thereby decreasing the possibility of the thread becoming inadvertently unthreaded from the thread guide, and a relatively wide groove opening at the bottom providing ample clearance for the free flow of thread in its respective groove. The grooves 22 run longitudinally along the entire member 20, as shown in FIG. 1, which allows for relatively easy threading of the thread guide. The fact that the surface area, with which the thread will come in contact, is composed of a plastic type material gives this area a certain degree of elasticity or flexibility and thus allows the lip members to resiliently retain the thread within the thread groove when it flows therethrough. This type of composition also presents a minimal amount of resistance to the thread flow thereby substantially decreasing the possibility of any thread breakage and uneven thread fiow.

The thread guide member 20 is formed with a rectangular recess 29 in its lower surface, as clearly shown in FIG. 2, which is adapted to receive a horizontal shank portion of the guide plates 19 and 25, which are in turn secured to the casing 9 by countersunk screw 28 as shown in FIG. 2. In the sewing machine illustrated in FIG. 1, it is important that the sewing threads be fully protected from contact with the fabric being sewn and therefore two thread guide units (20 and 26) are used. The threads are led through their respective thread grooves in unit 20 and thence from the guide plate 25 to the guide plate 25 of 4 unit 26. At the delivery end of unit 26 the threads are received in the funnel shaped member 30 and then travel to the lower stitch-forming devices (not shown).

From the above, it will be noted that there has been provided by the present invention in the most preferred embodiment thereof, a highly economical thread guide consisting only of a single plastic member which is readily threaded.

Having thus set forth the nature of the invention, what I claim is:

1. A sewing machine thread guiding device comprising an elongated member having a base, said member having a length substantially greater than its width, said base including a plurality of thread guiding grooves of the same size provided on one surface thereof, each of said grooves extending transversely from said one surface along the entire longitudinal axis of said member and in alignment with said axis, each of said grooves being defined by flexible lip means such that when the device is threaded by laterally introducing the thread along the longitudinal axis of said member into its coresponding groove the said lip means resiliently retains the thread within its respective groove, said lip means comprising a pair of upstanding walls, which define an open-ended groove,

symmetrically arranged on opposite sides of each groove relative to the longitudinal axis'of each of said grooves, and at least the surface area defining each of said grooves being composed of a plastic type material whereby a minimum resistance is presented by said material to the passage of thread through said device.

2. In a device in accordance with claim 1 in which the lip means comprises a pair of lip members which define an open-topped groove having a surface opening that is relatively narrower than the portion of the groove opening located opposite said surface opening.

3. In a device in accordance with claim 1 in which said lip means and said base member comprise an integral unit, both said lip means and said base member being composed of a plastic type material.

4. In a device in accordance with claim 3 in which said lip means and said base member are composed of a vinyl plastic material.

References Cited UNITED STATES PATENTS 1,996,040 3/1935 Clayton l12--63 3,054,277 9/1962 Broschar-d 661 3,203,387 8/1965 Fedevich 1122l8 FOREIGN PATENTS 958,340 9/ 1949 France. 1,166,070 6/1958 France.

r PATRICK D. LAWSON, Primary Examiner.

H. HAMPTON HUNTER, Assistant Examiner. 

